Abstract: The disclosure relates to a synthesis method of long carbon chain semi-aromatic nylon. The synthesis method comprises the following steps: mixing a wet powdery nylon salt, an antioxidant, a catalyst, a surfactant and pellets, and carrying out a one-step solid state polymerization under dynamic mixing to obtain a powdery nylon; under dynamic mixing, enabling the pellets to promote the stirring and mixing of the material and reducing material adhesion to the wall; the one-step solid state polymerization comprises a pre-solid state polymerization and a post-solid state polymerization; in the pre-solid state polymerization, ensuring the nylon salt and the prepolymer not to be molten; in the post-solid state polymerization, gradually reducing the system pressure to vacuum, and keeping the system pressure in vacuum state for at least 1 hour; the temperature of the post-solid state polymerization is not lower than the termination temperature of the pre-solid state polymerization.

Abstract: The present invention relates to a polymer film (P) containing a polyamide composition (PC) that comprises an amorphous polyamide (A) and a semicrystalline polyamide (B) and to a method for producing the polymer film (P). The present invention further relates to a method for packaging food products with the polymer film (P).

Abstract: A transparent polyimide film, prepared from a copolymerized polyamide acid according to a chemical cyclization method, is provided. The copolymerized polyamide acid requires at least a semi-aromatic polyamide acid, and the semi-aromatic polyamide acid is formed by reacting cyclobutane-1,2,3,4-tetracarboxylic dianhydride (CBDA) and 2,2?-bis(trifluoromethyl)diaminodiphenyl (TFMB). The molar number of dianhydrides of the semi-aromatic polyamide acid is more than 20% of the total molar number of anhydrides of the copolymerized polyamide acid, so that the transparent polyimide film has a light transmittance greater than 80%, a chroma b* less than 5, and a CTE less than 35 ppm/° C.

Abstract: Processes for preparing a polyamide, a polyamide material obtained by such processes, a nylon salt to be used therein, and processes for making the nylon salt are disclosed. The processes for preparing the polyamide include a direct solid state polymerization process. The salt used herein is a granulate material, prepared by a process, comprising spraying an aqueous solution comprising a diamine and a dicarboxylic acid dissolved in an aqueous medium, or an aqueous slurry comprising a diammonium dicarboxylate salt dispersed in an aqueous medium directly obtained from such an aqueous solution, onto or in a fluidized bed of diammonium dicarboxylate salt particles, while evaporating the aqueous medium, thereby forming a granulate salt material.

Abstract: Methods of making polymeric devices, such as stents, with one or more modifications such as addition of plasticizers, to improve processing, and the devices made by these methods.

Abstract: The present invention relates to reinforced polyamide molding materials which can be prepared from a polyamide blend and, for example, by compounding with cut fibers or continuous filaments on twin-screw extruders and have mechanical properties which are usually not compatible with one another, namely a combination of exceptionally high rigidity and strength and at the same time good toughness. Furthermore, a high heat distortion temperature (HDT) is achieved according to the invention. The thermoplastic polyamide molding materials according to the invention are suitable for the production of moldings or other semifinished products or finished articles, which can be produced, for example, by extrusion, injection molding, direct methods or direct compounding, in which the compounded polyamide molding material is processed directly by injection molding, or other deformation techniques.

Abstract: A method for producing a polyamine is described that provides excellent safety, a lot of flexibility regarding a variety of its productions, and that can produce a polyamine of high-molecular weight easily and inexpensively. The polyamine includes a combination of units of formula (1) or (2): —(NH—(CH2)m—NH—(CH2)n)—??(1) (in the formula (1), independently in every unit, “m” indicates an integral number of 0 or more and “n” indicates an integral number of 3 or more.) —(NH—Y—NH—Z)—??(2) (in the formula (2), independently in every unit, “Y” and “Z” are the same as or different from each other, and they indicate substituted or unsubstituted groups including unsaturated aliphatic, cyclic aliphatic or aromatic hydrocarbon radicals that can include hetero atoms.).

Abstract: The present invention is directed to a process for producing a polyamide, which process includes directly melt-polymerizing a diamine component including 70 mol % or more of p-xylylenediamine and a dicarboxylic acid component including 70 mol % or more of a C6 to C18 aliphatic dicarboxylic acid, in the absence of solvent in a batch-type reactor equipped with a stirring blade, the process including: (1) reacting the diamine component with the dicarboxylic acid component under a pressure condition of 0.2 to 0.5 MPa (Abs); (2) maintaining a vapor phase section of a reaction tank of the reactor at 200° C. or higher during reaction; (3) stirring the contents of the reaction tank, from the start of adding the diamine component until after completion of the addition and before the start of pressure falling, such that the stirring-related Froude number represented by a specific formula is adjusted to 0.0002 to 0.

Abstract: This is to provide a polyamide resin which can sufficiently ensure all of a relative viscosity ?r (high degree of polymerization), moldable temperature range estimated from a temperature difference (Td?Tm), heat resistance estimated from a melting point Tm, melt moldability estimated from a temperature difference (Tm?Tc), and low water absorbability as compared with the conventional polyoxamide resin. This is a polyamide resin comprising a dicarboxylic acid-derived unit and a diamine-derived unit being bonded, wherein the above-mentioned dicarboxylic acid contains oxalic acid (Compound A), and the above-mentioned diamine contains 1,6-hexanediamine (Compound B) and 2-methyl-1,5-pentanediamine (Compound C).

Abstract: A polyamide modified by a compound including a sulfonate group, as well as a method for preparing the polyamide and to articles obtained from said modified polyamide are described. A modified polyamide obtained from a mono-functional aromatic sulfonate compound is also described.

Abstract: A copolyamide resin for molding including a diamine component which includes two or more diamines and a dicarboxylic acid component. The diamine component includes 70 mol % or more of a xylylenediamine which includes 20 mol % or more of p-xylylenediamine and the dicarboxylic acid component includes 70 mol % or more of a straight-chain aliphatic dicarboxylic acid having 6 to 18 carbon atoms. The copolyamide resin contains particles having a major diameter of 50 ?m or more in an amount of 1000 particles/g or less, the particles being made of a polyamide having a melting point higher than that of the copolyamide resin by 20° C. or more when measured by a differential scanning calorimetry. The copolyamide resin has very uniform and stable properties and is excellent in any of mechanical properties, heat resistance, chemical and physical properties, and molding properties. An efficient production method of the copolyamide resin, its resin composition, and its molded article are also described.

Abstract: Absorbable polyurethanes, polyamides and polyester urethanes prepared from at least one compound selected from: or the corresponding diamines or diisocyanates thereof, wherein each X independently represents —CH2COO—, —CH(CH3)COO—, —CH2CH2OCH2COO—, —CH2CH2CH2CH2CH2COO—, —(CH2)yCOO— where y is 2 to 4 or 6 to 24, or —(CH2CH2O)z?CH2COO— where z? is 2 to 24; each Y represents —COCH2O—, —COCH(CH3)O—, —COCH2OCH2CH2O—, —COCH2CH2CH2CH2CH2O—, —CO(CH2)mO— where m is 2 to 4 or 6 to 24, or —COCH2O(CH2CH2O)n— where n is 2 to 24; R? is hydrogen, benzyl or straight-chained or branched alkyl; p is 1 to 4; and Rn represents one or more members selected from H, alkoxy, benzyloxy, aldehyde, halogen, carboxylic acid and —NO2, which is attached directly to an aromatic ring or attached through an aliphatic chain. Absorbable polymers prepared from these compounds are useful for drug delivery, tissue engineering, tissue adhesives, adhesion prevention and other implantable medical devices.

Abstract: Provided is a polyamide resin having high heat resistance, excellent moldability and excellent mechanical properties. The polyamide resin comprises a diamine unit containing 70 mol % or more of a xylylenediamine unit and a dicarboxylic acid unit containing 70 mol % or more of a straight chain aliphatic dicarboxylic acid unit, wherein the xylylenediamine unit is composed of 50 to 95 mol % of p-xylylenediamine and 50 to 5 mol % of m-xylylenediamine; the straight chain aliphatic dicarboxylic acid unit is composed of 50 to 100 mol % of adipic acid and 0 to less than 50 mol % of sebacic acid or other straight chain aliphatic dicarboxylic acids; the molar ratio of reacted diamine units to reacted dicarboxylic acid units (the number of moles of reacted diamine units/the number of moles of reacted dicarboxylic acid units) is less than 0.994; and the polyamide resin has a number average molecular weight of 10,000 to 25,000 and a melting point of 285° C. or more.

Abstract: A method of producing polyamide by the direct polycondensation of a diamine component and a dicarboxylic acid component without using a solvent, such as water. The diamine component containing 70 mol % or more of p-xylylenediamine is added to a reaction system containing the dicarboxylic acid component under pressure while maintaining the reaction system in a molten state. After the addition of the diamine component, the pressure of the reaction system is reduced to atmospheric pressure over 50 min or more at a pressure falling speed of 1.0 MPa/h or less. By the production method, polyamide with a small molecular weight dispersion is easily produced.

Abstract: A semi-aromatic polyamide including an aromatic dicarboxylic acid component, an aliphatic diamine component and a monocarboxylic acid component and having a melting point of 300° C. or higher, wherein the monocarboxylic acid component includes a monocarboxylic acid having a molecular weight of 140 or more, and the content of the monocarboxylic acid component is 1 to 8% by mass.

Abstract: The invention relates to a polyamide comprising recurring units derived from terephthalic acid and 1,10-decanediamine wherein said polyamide has an intrinsic melt viscosity of below 140.0 Pa·s and to compositions made there from, featuring high reflectivity in the molded part with high retention of whiteness and reflectivity after heat aging. This unique combination of properties makes the compositions according to the invention most suitable for LED applications.

Abstract: This invention relates to a biaxially stretched product comprising a copolyamide comprising monomeric units of: aliphatic non-cyclic diamines X and aliphatic non-cyclic dicarboxylic acids Y or aliphatic non-cyclic ?,?-amino acids Z, and diamines M and diacids N in an amount between 0.1 to 2 wt % based on the total amount of copolyamide, and in which M and N are cyclic, and wherein the product has been stretched at a temperature of between the glass transition temperature (Tg) and the melting temperature (Tm). A method of preparation is claimed, as well as a multilayer film comprising the biaxially stretched product.

Abstract: Provided is a thin-wall article formed from a polyamide resin which can be stably produced with little variation in mechanical properties such as flexural strength, flexural modulus and impact resistance. A thin-wall article formed by molding a polyamide resin (C) obtained by polycondensing a diamine (A) and a dicarboxylic acid (B) or a polyamide resin composition containing the polyamide resin, wherein 70 mol % or more of a diamine structural unit is derived from xylylenediamine and the polyamide resin has a melt viscosity (i) of 50 to 200 Pa·s as measured at a temperature of the melting point plus 10° C. for a holding time of 6 minutes at a shear rate of 122 sec?1.

Abstract: A modified long chain polyamide is provided. The modified long chain polyamide is polymerized by monomers comprising a long-aliphatic-chain monomer, and equimolar of an aromatic diacid and polyethyleneoxy diamine. A fiber made from the modified long chain polyamide is also provided.

Abstract: What is described is the use of a polyamide moulding composition for the production of a stain-resistant article, the staining tendency (ST) of the article being at least 2. Here, the composition contains 30-100% by weight of a polyamide or a polyamide mixture, consisting of 50-100% by weight of at least one amorphous and/or microcrystalline polyamide having a glass transition temperature of at least 100° C., based on: 20-100 mol % of at least one cycloaliphatic diamine; and 0-80 mol % of at least one other aliphatic and/or aromatic diamine; and also aromatic and/or aliphatic dicarboxylic acids comprising at least 6 carbon atoms, and 0-50% by weight of at least one semi-aromatic polyamide. In addition, 0-70% by weight of fibrous fillers (B1) and/or particulate fillers (B2), 0-30% by weight of impact toughness modifier and/or polymers different from (A), 0-25% by weight of a flame retardant, and 0-3% by weight of additives may also be contained.

Abstract: The invention is directed to a process for preparing polyamide polymers, particularly nylon 6, 6 and nylon 6, comprising fluoroether functionalized aromatic repeat units. In one embodiment, 1,6 diaminohexane, adipic acid, and fluoroether functionalized terephthallic or isophthallic acid or diester are reacted to form a polymer. The polymers so formed are useful for imparting soil resistance to polyamides, particularly in the form of films, molded parts, fibers, fabrics, and carpets.

Abstract: An S,S- and R,R-lactide stream suitable for polymerization is prepared by producing a low molecular weight poly(lactic acid), depolymerizing the low molecular weight poly(lactic acid) to form a mixture of S,S-, R,R- and meso-lactide, and separating meso-lactide from this mixture to form an S,S- and R,R-lactide stream. Meso-lactide is recycled into the process, and shifts the mole fractions of the lactides in the lactide mixture that is produced.

Abstract: The present invention relates to branched polyamides comprising unsaturated ends comprising: at least one unit originating from a multifunctional monomer (A) having more than two functional groups, at least sequences resulting from the condensation, in the presence of at least one unsaturated monoacid, either of at least two different lactams, or of at least one lactam, at least one dicarboxylic acid and at least one diamine, or of a lactam or of an ?,?-aminocarboxylic acid, or of a diamine and of a diacid. The invention also relates to thermofusible adhesives comprising these branched polyamides comprising unsaturated ends, and to the use of these branched polyamides comprising unsaturated ends in sheathing electrical cables.

Abstract: The present invention relates to stain- or dye-resistant light colored fibers, textiles and carpets made of a polymer composition (C) comprising at least one semi-aromatic polyamide comprising recurring units resulting from the condensation of terephthalic acid and at least one aliphatic diamine selected from the group consisting of 1,8-octanediamine, 1,9-nonanediamine, 2-methyl-1,8-octanediamine, 1,10-decanediamine, 1,12-dodecanediamine, 2,2,4-trimethyl-1,6-hexanediamine, 2,4,4-trimethyl-1,6-hexanediamine, 5-methyl-1,9-nonanediamine, methylcyclohexanediamine, isophoronediamine and mixtures thereof.

Abstract: Disclosed are a novel ionic organic compound and a method for producing the ionic organic compound by a simple process. Also disclosed are a hydrogelling agent composed of an ionic organic compound obtained by the method, an alcohol gelling agent, a gel which uses the gelling agent, while using water or methanol as a medium, and a carbon nanotube dispersant composed of the compound. Specifically disclosed is an ionic organic compound represented by general formula (1). The compound is obtained by a condensation reaction of (A) an aromatic diamide compound or cyclohexane diamide compound having a 4-(chloromethyl)benzamide group at both ends, and (B) a compound selected from N,N,N?,N?-tetramethylalkylenediamines which may have a substituent wherein there are 1-6 carbon atoms between nitrogen atoms. The thus-obtained ionic organic compound serves as a gelling agent which is capable of gelling a neutral aqueous solution or an alcohol.

Abstract: Provided is a polyamide resin having high heat resistance, excellent moldability and excellent mechanical properties. The polyamide resin comprises a diamine unit containing 70 mol % or more of a xylylenediamine unit and a dicarboxylic acid unit containing 70 mol % or more of a straight chain aliphatic dicarboxylic acid unit, wherein the xylylenediamine unit is composed of 50 to 95 mol % of p-xylylenediamine and 50 to 5 mol % of m-xylylenediamine; the straight chain aliphatic dicarboxylic acid unit is composed of 50 to 100 mol % of adipic acid and 0 to less than 50 mol % of sebacic acid or other straight chain aliphatic dicarboxylic acids; the molar ratio of reacted diamine units to reacted dicarboxylic acid units (the number of moles of reacted diamine units/the number of moles of reacted dicarboxylic acid units) is less than 0.994; and the polyamide resin has a number average molecular weight of 10,000 to 25,000 and a melting point of 285° C. or more.

Abstract: Disclosed is a polyamide composition including at least one semi-aromatic copolyamide, said semi-aromatic copolyamide consisting essentially of 40 to 60 mole percent repeat units of the formula —C(O)(CH2)4C(O)NHCH2ArCH2NH—??(I) and 40 to 60 mole percent repeat units of the formula —C(O)(CH2)4C(O)NH(CH2)6NH—??(II) wherein Ar is a meta-substituted benzene ring. Also disclosed are molded articles including the polyamide composition.

Abstract: Disclosed is a method for producing a nylon salt powder, wherein in the production of a nylon salt powder by allowing a dicarboxylic acid powder to react, the content of water is regulated to be 5% by mass or less in relation to the total amount of the dicarboxylic acid powder and a diamine, the dicarboxylic acid powder is beforehand heated to a temperature equal to or higher than melting point of the diamine and equal to or lower than the melting point of the dicarboxylic acid, and while this heating temperature is being maintained, the diamine is added to the dicarboxylic acid powder in such a way that the dicarboxylic acid powder maintains the condition of being in powder form.

Abstract: Provided is a xylylenesebacamide resin molding which is excellent in mechanical strength such as elastic modulus and avoids the problem of mechanical strength loss during long-term use. This is a molding of a polyamide resin or a polyamide resin composition containing the polyamide resin, wherein 70 mol % or more of the diamine structural unit is derived from xylylenediamine (A) and 50 mol % or more of the dicarboxylic acid structural unit is derived from sebacic acid (B), and the molding has a crystallinity index of 0 to 50% and a moisture content of 0.1 to 2% by mass.

Abstract: Disclosed herein is a method for preparing a polycondensation resin. The method includes preparing a low degree condensate; and solid phase polymerizing the low degree condensate, wherein a granular molded article is introduced into the solid phase polymerization. The method enables efficient manufacture of high quality resins without problems such as agglomeration or scaling of a low degree condensate in pipes.

Abstract: Provided is a polyamide resin composition comprising an elastomer etc, and a reactive polyamide resin excellent in reactivity. The polyamide resin composition comprises 0.5 to 100 parts by mass of an elastomer per 100 parts by mass of a reactive polyamide resin, wherein the reactive polyamide resin obtained by polycondensing a diamine (A) containing 70 mol % or more of a diamine structural unit derived from xylylenediamine and a dicarboxylic acid (B) containing 50 mol % or more of a dicarboxylic acid structural unit derived from sebacic acid, and has a concentration of reactive functional groups of 100 ?eq/g or more and a molar ratio of reacted diamine to reacted dicarboxylic acid (the number of moles of reacted diamine/the number of moles of reacted dicarboxylic acid) of 1.0 or more.

Abstract: The invention pertains to improved proppant particles comprising an aromatic polycondensation polymer having a glass transition temperature (Tg) of at least 120° C. when measured according to ASTM 3418 [polymer (P)] and a method of treating a subterranean formation using said proppant particles.

Abstract: The present invention relates to a semi-aromatic polyamide and a method for preparing it with low wastewater discharge. The semi-aromatic polyamide for the present invention is obtained by introducing aromatic dicarboxylic acid, aliphatic diamine containing 4˜14 carbon atoms and the wastewater generated during the previous prepolymerization into an autoclave for prepolymerization reaction and then further polymerizing the prepolymer. In this preparation method, the wastewater generated during polymerization is recycled, thus greatly reducing the wastewater discharge; the raw materials in the wastewater are effectively recycled, thus improving the utilization rate of raw materials; meanwhile, the diamine in the wastewater compensates that lost along with water discharge during prepolymerization, thus ensuring the Mole ratio balance between dicarboxylic acid monomer and diamine monomer.

Abstract: A method for producing an aqueous diamine dicarboxylic acid salt solution according to the present invention comprises a step of mixing a dicarboxylic acid diester and a diamine, wherein a mixing molar ratio of the diamine to the dicarboxylic acid diester (diamine/dicarboxylic acid diester) is 1.005 or more. In addition, a method for producing a polyamide according to the present invention comprises a step of mixing a dicarboxylic acid diester and a diamine and heating the formed aqueous diamine dicarboxylic acid salt solution to perform a polycondensation reaction of the diamine and a dicarboxylic acid, wherein a mixing molar ratio of the diamine to the dicarboxylic acid diester (diamine/dicarboxylic acid diester) is 1.005 or more.

Abstract: An adhesive agent comprising a condensation resin having a structural unit obtained by polycondensing a polymerizable monomer containing a monomer (A) having 2 or more carboxyl groups and a monomer (B) having 2 or more amino groups, and meeting at least one of the following (1) and (2), and the following (3): (1) at least one selected from the group consisting of the monomer (A), an anhydride of the monomer (A). and the monomer (B) is liquid at 25° C.; (2) the condensation resin has a polyoxyalkanediyl group; and (3) the monomer (A) contains an isophthalic acid.

Abstract: This invention relates to compositions, and the use of such compositions for protective coatings, particularly of electronic devices. The invention concerns fired-on-foil ceramic capacitors coated with a composite encapsulant and embedded in a printed wiring board.

Abstract: The semiaromatic polyamide of the present invention includes a terephthalic acid component and a diamine component, wherein the diamine component is any of 1,8-octanediamine, 1,10-decanediamine and 1,12-dodecanediamine, and the proportion of the triamine unit in relation to the diamine unit in the polyamide is 0.3 mol % or less.

Abstract: A polyamic acid composition including a polyamic acid, the polyamic acid having an imidization ratio of from about 5.0% to about 25.0%, and being obtained by reacting a diamine compound, a tetracarboxylic dianhydride and an acid monoanhydride at an amount ratio that satisfies the following formula (1): 0.970<Y/X<0.998 and Formula (2): 0.00<Z/2(X?Y)<0.50. In Formula (1) and Formula (2), X represents a content (mol) of the diamine compound, Y represents a content (mol) of the tetracarboxylic dianhydride, and Z represents a content of the acid monoanhydride (mol).

Abstract: Polyamide having a melting point between 330° C. and 370° C., said polyamide comprising: a diamine component (a) comprising between 0 and 55 mole %, based on the total number of moles of the diamine component (a), of at least one aliphatic diamine having more than 6 carbon atoms, and between 45 and 100 mole %, based on the total number of moles of the diamine component (a), of at least one aliphatic diamine having at most 6 carbon atoms, and a dicarboxylic acid component (b) comprising more than 50 mole %, based on the total number of moles of the dicarboxylic acid component (b), of terephthalic acid, with the exception of a certain specific polyamide (P*).

Abstract: A process for producing polyamide which comprises directly melt polymerizing a diamine component, which comprises 70% by mole or more of xylylenediamine comprising 20% by mole or more of para-xylylenediamine, and a dicarboxylic acid component in the substantial absence of solvents in a reaction apparatus of the batch type, wherein a stirring apparatus disposed in the reaction apparatus and used for stirring the melted polymer in the apparatus comprises: (1) a rotating shaft connected to a driving member for stirring, (2) two or more stirring rods disposed in the substantially vertical direction which are cylinder-shaped members or plate-shaped members moving along the circumference of a circle having the center at the rotating shaft, and (3) a connecting member which connects the rotating shaft and the stirring rods; distances between the center line of the rotating shaft and center lines of the two or more stirring rods are each 15% or greater of the inner diameter of the reaction apparatus; the connecting m

Abstract: An economical batchwise production method of polyamide with good quality by the polycondensation in which a diamine component including 70 mol % or more of a xylylenediamine which includes 20 mol % or more of p-xylylenediamine is added to a dicarboxylic acid component in a batchwise reaction tank equipped with a partial condenser. The diamine component is added while maintaining the whole reaction system in fluid state under pressure. The pressure is reduced during the time that the molar ratio is within a specific range while continuing the addition.

Abstract: The invention relates to a polyesteramide resin containing ester groups and at least one amide group in the back-bone characterized in that it has at least one hydroxyalkylamide endgroup, and a Tg<0° C.

Abstract: A fuser member and image forming apparatus including the fuser member for use in oil-less systems, wherein the fuser member includes a substrate, and thereover, an outer layer having a fluorinated polyimide of the following Formula I: wherein Ar independently represents a fluorinated hydrocarbon group, Rf2 and Rf3 individually represent a fluorine-containing group, L represents a linkage group, l and m each individually represent a mole fraction of repeating units, wherein the value ranges from about 0.1 to about 0.99, p represents an integer ranging from about 20 to about 1,000, Q is an end group, and o is 0 or 1.

Abstract: A metal-coated polyimide film is excellent in long-term adhesion reliability, exhibits various dimensional stabilities, and is particularly suitable for FPC, COF and TAB applications. The metal-coated polyimide film comprises a non-thermoplastic polyimide film; and a metal layer being directly formed on one surface or both surfaces of the non-thermoplastic polyimide film without using an adhesive, wherein the non-thermoplastic polyimide film contains a non-thermoplastic polyimide resin having a thermoplastic polyimide block component.

Abstract: The invention relates to a housing from a polyamide molding compound containing 70 to 99.5% by weight of at least one thermoplastic polyamide and 0.5 to 30% by weight of at least one polyamide oligomer with linear or branched chain structure with a number average molar mass of 800 to 5000 g/mol with basic end groups which are at least partially NH2 end groups, and carboxyl end groups, one of these end groups being present in excess and the concentration of the end group present in excess being at most 300 mmol/kg.

Abstract: A method for making polyamide is described. More particularly, a method for making a polyamide from at least one diacid and one diamine, that includes a step of concentrating an aqueous solution of diacid and diamine salt up to a salt weight concentration higher than 85%, and a polymerization step up to a desired polymerization degree is described.

Abstract: An objective is to provide a method of forming a piezoelectric resin film produced at low cost, and specifically to provide the method in which a large-area piezoelectric resin film is produced at low cost, and at reduced investment in facilities. Disclosed is a method of forming a piezoelectric resin film possessing the steps of polymerizing a monomer at a temperature of 5-60° C. to obtain a resin having a polymerization degree of 4-300, and a polarity group possessing one bond selected from a urea bond, an ester bond, an amide bond and an imide bond, coating the resin onto a substrate; and further polymerizing the resin at 70-250° C. while conducting a poling treatment.

Abstract: A method of producing polyamide by the direct polycondensation of a diamine component and a dicarboxylic acid component without using a solvent, such as water. The diamine component containing 70 mol % or more of p-xylylenediamine is added to a reaction system containing the dicarboxylic acid component under pressure while maintaining the reaction system in a molten state. After the addition of the diamine component, the pressure of the reaction system is reduced to atmospheric pressure over 50 min or more at a pressure falling speed of 1.0 MPa/h or less. By the production method, polyamide with a small molecular weight dispersion is easily produced.

Abstract: Disclosed is a fluorine-containing dicarboxylic acid represented by formula (1), wherein n represents an integer of 1-4, and the two carboxylic groups are not adjacent to each other on the aromatic ring. It is possible to obtain a linear polymer compound by reacting the fluorine-containing dicarboxylic acid with a comonomer (e.g., diaminodiol). By thermal cyclization, this linear polymer compound can be converted into another polymer compound having superior characteristics.

Abstract: The invention relates to a polyamide comprising at least two units having the following general formula: 4.Y in which: 4 denotes butanediamine, and Y represents a dicarboxylic acid chosen from a linear or branched aliphatic dicarboxylic acid, a cycloaliphatic diacid and an aromatic diacid, the dicarboxylic acid containing from 7 to 11 carbon atoms, the butanediamine contains carbon of renewable origin, except for the fact that when the polyamide is a copolyamide, it cannot contain 100% by mass of organic carbon derived from renewable raw materials relative to the total mass of polyamide carbon. The invention also relates to a composition comprising this polyamide and the use of this polyamide and of such a composition.